Field
This disclosure relates generally to semiconductor devices, and more specifically, to a method of detecting low strength in an interlayer dielectric (ILD) structure.
Related Art
In modern semiconductor technologies, a major packaging challenge is delamination and cracking of Low-k and Ultra-Low-k (ULK) ILD films in the back end of line (BEOL) stack during or after packaging processing steps. This delamination is a result of the reduced strength of these new ILD films (both adhesive and cohesive strength) combined with stresses introduced by packaging materials with significantly different thermal expansion coefficients. The delamination failure mode is difficult to detect as an electrical signature is not always immediately present, and the separation caused by the delamination can be on the order of 50 microns or less. Furthermore, natural variation in wafer fabrication processes can result in a further reduced strength of some wafers and low level failure rates.